avoid dbengine event loop starvation by running uv_run periodically (n…

…etdata#19661)
webfutureiorepo · Feb 17, 2025 · 12930b2 · 12930b2
1 parent c19ae2a
commit 12930b2
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Showing 2 changed files with 14 additions and 5 deletions.
diff --git a/src/database/engine/rrdengine.c b/src/database/engine/rrdengine.c
@@ -524,18 +524,19 @@ static inline bool rrdeng_cmd_has_waiting_opcodes_in_lower_priorities(STORAGE_PR
 static inline struct rrdeng_cmd rrdeng_deq_cmd(bool from_worker) {
     struct rrdeng_cmd *cmd = NULL;
     enum LIBUV_WORKERS_STATUS status = work_request_full();
-
     STORAGE_PRIORITY min_priority, max_priority;
-    min_priority = STORAGE_PRIORITY_INTERNAL_DBENGINE;
-    max_priority = (status != LIBUV_WORKERS_RELAXED) ? STORAGE_PRIORITY_INTERNAL_DBENGINE : STORAGE_PRIORITY_INTERNAL_MAX_DONT_USE - 1;
 
-    if(from_worker) {
+    if(unlikely(from_worker)) {
         if(status == LIBUV_WORKERS_CRITICAL)
             return opcode_empty;
 
         min_priority = STORAGE_PRIORITY_INTERNAL_QUERY_PREP;
         max_priority = STORAGE_PRIORITY_BEST_EFFORT;
     }
+    else {
+        min_priority = STORAGE_PRIORITY_INTERNAL_DBENGINE;
+        max_priority = (status != LIBUV_WORKERS_RELAXED) ? STORAGE_PRIORITY_INTERNAL_DBENGINE : STORAGE_PRIORITY_INTERNAL_MAX_DONT_USE - 1;
+    }
 
     // find an opcode to execute from the queue
     spinlock_lock(&rrdeng_main.cmd_queue.unsafe.spinlock);
@@ -1916,7 +1917,15 @@ void dbengine_event_loop(void* arg) {
         uv_run(&main->loop, UV_RUN_DEFAULT);
 
         /* wait for commands */
+        size_t count = 0;
         do {
+            count++;
+
+            if(count % 100 == 0) {
+                worker_is_idle();
+                uv_run(&main->loop, UV_RUN_NOWAIT);
+            }
+
             worker_is_busy(RRDENG_OPCODE_MAX);
             cmd = rrdeng_deq_cmd(RRDENG_OPCODE_NOOP);
             opcode = cmd.opcode;

diff --git a/src/database/storage-engine.h b/src/database/storage-engine.h
@@ -17,12 +17,12 @@ typedef enum __attribute__ ((__packed__)) storage_priority {
     // query priorities
     STORAGE_PRIORITY_HIGH,
     STORAGE_PRIORITY_NORMAL,
+    STORAGE_PRIORITY_SYNCHRONOUS_FIRST,
     STORAGE_PRIORITY_LOW,
     STORAGE_PRIORITY_BEST_EFFORT,
 
     // synchronous query, not to be dispatched to workers or queued
     STORAGE_PRIORITY_SYNCHRONOUS,
-    STORAGE_PRIORITY_SYNCHRONOUS_FIRST,
 
     STORAGE_PRIORITY_INTERNAL_MAX_DONT_USE,
 } STORAGE_PRIORITY;